Glossary名詞表

Every term defined in the chapters, with its one-line definition and a link to the paragraph where it is introduced. 104 terms.各章定義的每個名詞，附一行定義與連到引入它的段落的連結。共 104 個名詞。

+Grid+Grid Ch. 2: The topology that links each satellite to its two intra-plane neighbors and the same-index satellite in each adjacent plane.; 把每顆衛星連到同面的兩個鄰居，以及相鄰兩面中同一編號衛星的拓樸。
Acquisition擷取 Ch. 2: The search phase in which two terminals find each other's beams before data transfer. Current acquisition takes seconds to tens of seconds.; 兩個終端在資料傳輸前搜尋並找到彼此光束的階段，目前需要數秒到數十秒。
Activation compression激活值壓縮 Ch. 12: Sparsifying, quantizing and entropy-coding the tensor that crosses a layer boundary between two devices.; 對跨越兩個裝置之間層邊界的張量做稀疏化、量化與熵編碼。
all-reduce全歸約（all-reduce） Ch. 10: The collective in which every worker ends with the element-wise sum of all workers' vectors.; 讓每個工作者最後都拿到所有工作者向量逐元素總和的集體通訊。
Aperture口徑 Ch. 2: The diameter of the telescope that transmits or collects a beam. Gain scales with the square of this diameter.; 發射或收集光束的望遠鏡直徑，增益與口徑的平方成正比。
BBRBBR Ch. 6: A model-based controller that sets the sending rate from estimated bottleneck bandwidth and minimum RTT.; 以模型為基礎的控制器，依估計的瓶頸頻寬與最小 RTT 決定傳送速率。
Beam波束 Ch. 3: A steerable radio spot formed by a satellite's array. The array forms many beams at once.; 衛星陣列形成的可轉向電波光斑，一顆衛星可同時形成多個波束。
Bent pipe彎管轉送 Ch. 3: A path through one satellite: terminal → satellite → gateway within the same footprint. The path uses ground links for both hops.; 終端 → 衛星 → 同一覆蓋區內閘道的路徑，兩跳皆為地面與單一衛星之間的鏈路。
Bisection capacity對分容量 Ch. 5: The summed link capacity across the cut that splits a network into two halves.; 把網路切成兩半的割集上所有鏈路容量之和。
bisection intensity對切強度 Ch. 10: Floating-point operations per step divided by bytes that must cross the bisection per step.; 每一步的浮點運算量，除以每一步必須穿越對切面的位元組數。
Bufferbloat緩衝區膨脹 Ch. 3: Latency inflation caused by a large standing queue, 2–4× the idle RTT on a loaded Starlink link.; 由大型常駐佇列造成的延遲膨脹，在負載下的 Starlink 鏈路上達到閒置 RTT 的 2–4 倍。
Cell服務格 Ch. 3: The ground area whose users are served together by a beam, roughly 24 km across in Starlink.; 由同一波束一起服務的地面區域，在 Starlink 中直徑約 24 km。
Clos networkClos 網路 Ch. 10: A layered switch fabric in which compute nodes attach to leaf switches and every leaf reaches every other through spine switches.; 一種分層交換架構：運算節點接到葉交換器，每個葉交換器都透過脊交換器到達其他所有葉交換器。
Cluster fabric叢集網路架構 Ch. 11: The network inside a formation cluster: terminals per satellite, switching and the topology that links them.; 編隊叢集內部的網路：每顆衛星的終端數、交換方式，以及連接它們的拓樸。
Congestion control壅塞控制 Ch. 6: The sender-side algorithm that sets how much data may be in flight from the signals the network returns.; 傳送端根據網路回傳的訊號決定可以有多少資料在途中的演算法。
Congestion window (cwnd)壅塞視窗（cwnd） Ch. 6: The sender's limit on unacknowledged bytes, so that throughput is at most cwnd divided by the RTT.; 傳送端允許在途並等待確認的位元組數上限，吞吐量最多為 cwnd 除以 RTT。
Consistent hashing一致性雜湊 Ch. 9: A hash maps each object to one of N buckets, and each bucket maps to one cache. Requests reach the cache holding the object's single copy.; 雜湊函數將每個物件分配到 N 個桶之一，每個桶再對應一台快取。這組快取只儲存每個物件的一份副本，並將請求送往持有該物件的快取。
Content delivery network (CDN)內容遞送網路（CDN） Ch. 9: Caches near users that serve popular objects locally, reducing requests to the origin server.; 部署在使用者附近的一組快取，從近處提供熱門內容，減少向來源伺服器擷取資料。
CUBICCUBIC Ch. 6: The loss-driven Linux default that cuts the window on loss and regrows it along a cubic curve.; 以遺失為訊號的 Linux 預設演算法，遺失時縮小視窗，再沿三次曲線回升。
Decode解碼（decode） Ch. 12: The second phase, generating one output token per step, each step depending on the last.; 第二階段，每一步產生一個輸出 token，每一步依賴前一步。
Depth of discharge放電深度（DoD） Ch. 8: The fraction of a battery's capacity drawn each cycle, traded against cycle life.; 每個循環取用的電池容量比例，與循環壽命互為取捨。
Digital twin數位孿生 Ch. 7: An emulation whose constellation, ground stations and link states are built from real data such as filings and TLEs.; 由申報文件與 TLE 等真實資料建構星座、地面站與鏈路狀態的模擬平台。
Direct-to-cell (D2C)直連手機（D2C） Ch. 3: Service from a satellite to an unmodified mobile phone in a terrestrial cellular band.; 衛星使用地面行動通訊頻段，直接服務維持原廠配置的手機。
Divergence發散角 Ch. 2: The full angle over which a beam spreads, about 1.22λ/D for an aperture D.; 光束擴散的全角，對口徑 D 約為 1.22λ/D。
Doppler shift多普勒頻移 Ch. 2: The optical frequency offset vr/λ caused by range rate. At 1,550 nm, each km/s produces a 0.645 GHz shift.; 距離變化率造成的光頻偏移 vr/λ，在波長 1,550 nm 時，每 km/s 對應 0.645 GHz。
Downlink bottleneck下行瓶頸 Ch. 8: The limit set by pass minutes times station rate on how much a satellite can send to the ground per orbit.; 由過頂分鐘數乘以地面站速率決定的每圈可下傳資料量上限。
Drop-front queue前端丟棄佇列 Ch. 3: A queue that discards its oldest packet when full and admits the arriving packet.; 滿載時丟棄最舊封包，並接納新到封包的佇列。
Duty cycle工作週期 Ch. 8: The fraction of time a payload runs when heat or energy forces it to pause.; 當散熱或能量迫使酬載暫停時，酬載實際運行的時間比例。
DWDMDWDM Ch. 2: Dense wavelength-division multiplexing: many independent channels on one beam, spaced 100 GHz or less apart.; 高密度分波多工：在同一道光束上放多個獨立通道，間距 100 GHz 或更小。
Eclipse地影 Ch. 1: The part of each orbit spent in Earth's shadow.; 每一圈軌道中位於地球陰影內的部分。
Elevation angle仰角 Ch. 1: The satellite's angle above the user's local horizon. The elevation mask sets the minimum permitted angle.; 衛星高於使用者當地地平線的角度，仰角遮罩設定營運商允許的最低值。
Emulator模擬平台（emulator） Ch. 7: A testbed that runs standard operating systems and applications in real time. A model sets each link's delay and rate.; 以實際時鐘執行原版作業系統與應用程式，並由模型設定鏈路延遲與速率的測試平台。
evidence tag證據標籤 Ch. 4: A label attached to a number stating what kind of document it comes from and therefore how a reader can check it.; 附在數字上的標記，說明它來自哪一類文件，因此讀者能用什麼方式查證。
Expert placement專家配置 Ch. 12: The assignment of experts to satellites so that the hidden state travels the shortest expected path.; 把專家指派到衛星上，讓隱藏狀態走的期望路徑最短。
exposed communication暴露的通訊 Ch. 10: Communication that extends a step because it occurs outside the time spent on computation.; 發生在運算時段之外、因此直接延長步驟耗時的通訊。
Federated learning聯邦學習 Ch. 9: Training in which participants update a shared model using local data. They exchange only model updates with an aggregator, keeping training data local.; 每個參與者使用本地資料訓練共享模型，只向彙總者傳送模型更新，訓練資料留在本地。
filing snapshot申報快照 Ch. 4: The constellation geometry stated in one dated regulatory document, which later filings replace and which the papers of its year freeze.; 某一份附日期監管文件中陳述的星座幾何，之後的申報會取代它，而當年的論文則把它凍結下來。
Formation flying編隊飛行 Ch. 11: Several satellites controlled so that their relative positions follow a prescribed, repeating geometry.; 多顆衛星受控制，使其相對位置遵循預先設定、週期重複的幾何。
Gateway閘道站 Ch. 3: A ground station of several parabolic dishes that carries the satellite's traffic to and from the terrestrial network.; 由數個拋物面天線組成的地面站，把衛星的流量送往地面網路並接回。
Geographic routing地理路由 Ch. 5: Routing that uses identifiers for Earth-fixed cells as its address reference.; 以地球固定格元的代碼作為位址依據的路由方式。
Ground relay地面中繼 Ch. 5: A ground station that receives from one satellite and retransmits to another, replacing an ISL hop.; 從一顆衛星接收再轉發給另一顆衛星的地面站，用來取代一跳星間鏈路。
Handover換手 Ch. 3: The moment a terminal switches from one serving satellite to another.; 終端從一顆服務衛星切換到另一顆的時刻。
HCW equationsHCW 方程 Ch. 11: The Hill–Clohessy–Wiltshire linearised equations of relative motion about a circular reference orbit.; Hill–Clohessy–Wiltshire 方程，描述繞圓形參考軌道的相對運動的線性化方程。
Hop count跳數 Ch. 5: The number of inter-satellite links a packet crosses, used as a proxy for capacity consumption.; 封包穿越的星間鏈路數，是所消耗容量的代理指標。
ICI晶片間互連（ICI） Ch. 10: The inter-chip interconnect that directly links accelerators inside one host or pod, bypassing network interface cards.; 繞過網路卡，直接連接同一主機或同一 pod 內加速器的晶片間互連。
Inclination傾角 Ch. 1: The angle between the orbital plane and the equator, which bounds the satellite's latitude range.; 軌道面相對赤道的傾斜角，決定衛星能到達的最高緯度。
Inter-satellite link (ISL)星間鏈路（ISL） Ch. 2: A direct radio or laser link between satellites that carries traffic across the constellation entirely in space.; 兩顆衛星之間的直接電波或雷射鏈路，讓流量全程在太空中穿越星座。
J₂J₂ 項 Ch. 11: The oblateness term of Earth's gravity field, the dominant perturbation that drifts relative orbits apart.; 地球重力場的扁率項，是使相對軌道漂移分離的主要攝動。
KV cacheKV 快取 Ch. 12: The keys and values that each attention layer stores per token. Decode reuses them to avoid repeated prompt computation.; 每個注意力層按 token 儲存的 key 與 value，解碼時可重用提示的計算結果。
Link budget鏈路預算 Ch. 2: The accounting, in decibels, of transmit power, antenna gains and losses that yields received power.; 以分貝記帳發射功率、天線增益與各項損耗，最後得到接收功率的計算。
Low Earth orbit (LEO)低地球軌道（LEO） Ch. 1: Orbits below about 2,000 km altitude, where broadband constellations fly.; 高度約 2,000 km 以下的軌道，寬頻星座都在這裡飛行。
Mixture of experts (MoE)混合專家（MoE） Ch. 12: A transformer whose feed-forward block is split into experts of which a router activates only a few per token.; 前饋區塊被切成多個專家、每個 token 只由路由器啟用其中少數幾個的 transformer。
MotifMotif Ch. 2: A local link pattern repeated identically by every satellite, searched over as an alternative to +Grid.; 每顆衛星都以相同方式重複的局部連線樣式，作為 +Grid 之外的搜尋對象。
Near field近場 Ch. 2: Distances below an aperture's Fresnel distance, where the beam remains concentrated and calculations require a near-field model.; 距離小於口徑的 Fresnel 距離、光束仍集中的範圍，計算時需採近場模型。
Nodal precession升交點進動 Ch. 1: Slow drift of the ascending node caused by Earth's oblateness (J₂).; 地球扁率（J₂）造成的升交點緩慢漂移。
Node delay節點延遲 Ch. 2: The time between a packet's arrival and departure on separate satellite links. The Starlink value awaits measurement.; 封包從一條鏈路進入衛星，至另一條鏈路離開的耗時，Starlink 的數值仍待量測。
OFDM frameOFDM 幀 Ch. 3: The repeating 1.333 ms unit of the Starlink downlink: sync symbols, header, then data symbols over 1,024 subcarriers.; Starlink 下行每 1.333 ms 重複一次的單位：同步符號、標頭，然後是分佈在 1,024 個子載波上的資料符號。
On-board inference機上推論 Ch. 9: Inference on a satellite's processor, with only the results sent over the downlink and raw data kept on board.; 在衛星處理器上執行訓練好的模型，只將結果下傳，原始資料留在衛星上。
Orbital data center軌道資料中心 Ch. 13: A formation of compute satellites joined by short-range optical links into one cluster, with its own ground segment and user path.; 一群以短距光鏈路連成單一叢集的運算衛星，連同自己的地面段與使用者路徑。
Orbital edge computing軌道邊緣運算（OEC） Ch. 8: Inference on a satellite, with only the results sent to the ground and raw sensor data kept on board.; 在衛星上執行推論，只將結果下傳，原始感測資料留在衛星上。
Orbital period軌道週期 Ch. 1: Time for one revolution, fixed by altitude alone for a circular orbit.; 繞行一圈所需的時間，圓軌道時只由高度決定。
Orbital plane軌道面 Ch. 1: The plane containing one orbit, located by its inclination and ascending node.; 包含一條軌道的平面，由傾角與升交點定位。
oversubscription超額訂閱 Ch. 10: The ratio of capacity entering a network tier to capacity leaving it upward.; 進入某一層網路的容量，與該層向上送出容量之間的比值。
Packet simulator封包模擬器 Ch. 7: Software that advances a model network event by event in simulated time, with every protocol and link written as a model.; 在模擬時間中逐一事件推進模型網路的軟體，每一個協定與鏈路都是寫出來的模型。
parameter sheet參數表 Ch. 4: The single dated table of every constant an evaluation rests on, each with its value, provenance and date.; 一份附日期的表，列出評估所依賴的每個常數及其數值、出處與日期。
Pass過頂 Ch. 1: The interval during which one satellite stays above the elevation mask.; 一顆衛星停留在仰角遮罩之上的時間區間。
Path emulator路徑模擬平台 Ch. 6: A testbed that replays one pre-computed satellite path, with its delay, capacity and handover schedule, under a real operating-system network stack.; 在真實作業系統網路堆疊下，重現一條預先算好的衛星路徑及其延遲、容量與換手排程的測試平台。
Phase offset相位偏移 Ch. 1: The along-track shift between satellites in neighboring planes, 360·f/t degrees.; 相鄰軌道面衛星之間沿軌方向的錯位，等於 360·f/t 度。
Phased array相位陣列 Ch. 3: A flat antenna whose elements steer a beam electronically through their relative phases. The dish stays mechanically fixed.; 由許多元件組成的平板天線，藉由相對相位以電子方式轉向波束，碟盤維持固定。
Point of presence (PoP)網路接入點（PoP） Ch. 3: The point where an operator's network passes traffic to the public Internet. Every Starlink flow reaches a PoP through a tunnel.; 業者網路將流量交給公共網際網路的地點，每條 Starlink 流量都經隧道抵達某個 PoP。
Point-ahead angle預指向角 Ch. 2: The offset 2vt/c between where a partner is seen and where the beam must be sent, because light takes time to arrive.; 因光需要時間抵達，光束必須送往的方向與看到對象的方向之間相差的角度 2vt/c。
Pointing, acquisition and tracking (PAT)指向、擷取與追蹤（PAT） Ch. 2: The control problem of aiming a microradian beam at a partner thousands of kilometres away and holding it there.; 把微弧度級的光束對準數千公里外的對象並持續鎖住的控制問題。
Prefill預填（prefill） Ch. 12: The first phase of serving a request, in which every prompt token passes through the model at once.; 服務一個請求的第一階段，提示的所有 token 一次通過模型。
Propagation delay傳播延遲 Ch. 2: Distance divided by light speed in the medium. In vacuum, propagation takes 3.336 µs per kilometer.; 距離除以介質中的光速，在真空中每公里需要 3.336 µs。
Radiator輻射散熱板 Ch. 8: The surface that sheds a satellite's waste heat as infrared, at a rate set by its temperature to the fourth power.; 把衛星廢熱以紅外線輻射出去的表面，速率由溫度的四次方決定。
Rain fade雨衰 Ch. 3: Extra attenuation of a Ku- or Ka-band link while rain lies on the path, seen in Starlink as a 17–27% throughput drop.; 當路徑上有雨時 Ku 或 Ka 頻段鏈路的額外衰減，在 Starlink 上表現為 17–27% 的吞吐量下降。
Reconfiguration interval重新配置週期 Ch. 3: The 15-second period on which Starlink's global scheduler reassigns satellites and resources, at seconds :12, :27, :42 and :57.; Starlink 全域排程器重新指派衛星與資源的 15 秒週期，落在每分鐘的第 12、27、42、57 秒。
Reconfiguration-aware congestion control感知重新配置的壅塞控制 Ch. 6: A controller that learns, predicts or infers the satellite network's scheduled changes and discounts the loss and delay signals they produce.; 能得知、預測或推斷衛星網路排程變動，並對其產生的遺失與延遲訊號打折扣的控制器。
Relative orbit相對軌道 Ch. 11: The closed path a satellite traces in the rotating frame attached to a reference satellite.; 衛星在附著於參考衛星的旋轉座標系中所描出的封閉路徑。
Research question研究問題 Ch. 13: A question stated with the measurement or simulation that could show it false and the baseline it must beat.; 同時列出檢驗假設所需量測或模擬，以及必須超越之基準的問題。
Seam接縫 Ch. 1: Where the first and last planes of a Star pattern meet moving in opposite directions.; Star 型星座中第一與最後一個軌道面相遇、彼此反向運動的地方。
SGP4SGP4 Ch. 7: The standard propagator that turns a TLE into a position and velocity at any later time.; 把 TLE 轉換成之後任意時刻位置與速度的標準軌道推算器。
Shell殼層 Ch. 1: A group of planes sharing one altitude and inclination, filed and operated as a unit.; 共享同一高度與傾角的一組軌道面，在申請與營運上視為一個單位。
Silent data corruption (SDC)靜默資料損毀（SDC） Ch. 8: An incorrect computational result that the system accepts silently.; 系統靜默接受的錯誤計算結果。
Single-event effect (SEE)單粒子效應（SEE） Ch. 8: A fault caused by one particle, from a flipped bit to a destructive latch-up.; 單一粒子造成的故障，從位元翻轉到破壞性閂鎖都算。
Single-event functional interrupt (SEFI)單粒子功能中斷（SEFI） Ch. 8: A single-event fault that halts a device until it is reset or power-cycled.; 使裝置停擺、直到重置或斷電重啟才恢復的單粒子故障。
Slant range斜距 Ch. 1: Straight-line distance from user to satellite, which sets the propagation delay.; 使用者到衛星的直線距離，決定傳播延遲。
Spatial multiplexing空間多工 Ch. 11: Splitting one aperture into an array of smaller sub-apertures, each carrying an independent beam, at the price of range.; 將一個口徑分割為多個較小子口徑的陣列，每個子口徑承載獨立光束，代價是縮短距離。
Specific power比功率 Ch. 8: Watts of array output per kilogram of array mass.; 每公斤陣列質量所產生的瓦數。
Staleness陳舊度 Ch. 9: The number of global rounds that have passed between a participant downloading a model and its update being aggregated.; 參與者下載模型到它的更新被彙總之間，已經過去的全局回合數。
step time步時間 Ch. 10: The elapsed time for one training step: computation plus communication that extends beyond it.; 一個訓練步驟的實際耗時，等於運算時間加上延伸至運算時段之外的通訊時間。
Stretch伸長比 Ch. 5: Path latency or length divided by the great-circle value between the same endpoints.; 路徑延遲或長度除以同一對端點之間的大圓值。
Sun-synchronous orbit (SSO)太陽同步軌道（SSO） Ch. 1: A retrograde orbit whose nodal precession matches the Sun's apparent motion.; 升交點進動速率與太陽視運動相同的逆行軌道。
Switch satellite交換衛星 Ch. 11: A satellite assigned to switching in a Clos network, which occupies a position otherwise available to a compute satellite.; 在 Clos 網路中專責交換的衛星，會占用原本可配置運算節點的位置。
Temporary ISL暫時性星間鏈路 Ch. 2: A link to a satellite that is only briefly within range, such as one in a crossing plane.; 與只短暫進入範圍的衛星（例如交叉軌道面上的衛星）之間的鏈路。
Time per token每 token 時間 Ch. 12: The wall-clock time one decode step takes for one request stream, the inference analogue of step time.; 單一請求串流中一個解碼步驟所需的時鐘時間，相當於訓練中的步驟時間。
TLE兩行軌道根數（TLE） Ch. 7: Two-line element set: the public text format of a satellite's orbital elements at an epoch.; 兩行軌道根數：某顆衛星在某個曆元時刻軌道根數的公開文字格式。
Topology holding time拓樸維持時間 Ch. 5: How long the link graph stays unchanged before some link appears or disappears.; 從鏈路圖形成至下一條鏈路出現或消失的時間區間。
torus環面（torus） Ch. 10: A grid in which each node links to its neighbors in every dimension and the edges wrap around.; 每個節點都與各維度的鄰居相連、且邊緣首尾相接的網格。
Total ionising dose (TID)總游離劑量（TID） Ch. 8: Cumulative radiation absorbed by silicon, in rad(Si), which degrades devices gradually.; 矽累積吸收的輻射量，以 rad(Si) 計，使元件逐漸退化。
Traffic engineering流量工程 Ch. 5: The allocation of each traffic demand across candidate paths so that every link stays within capacity.; 分配每項需求在各候選路徑上的流量，使各鏈路維持在容量範圍內。
User link使用者鏈路 Ch. 3: The radio link between a subscriber terminal and the satellite, as opposed to the gateway (feeder) link.; 使用者終端與衛星之間的電波鏈路，與閘道端的饋線鏈路分屬兩類。
Vantage point觀測點 Ch. 7: A host from which measurements of the network are taken.; 對網路進行量測的那一台主機。
Walker notationWalker 記法 Ch. 1: i: t/p/f describes a symmetric constellation by inclination, total, planes and phasing.; 以 i: t/p/f 描述對稱星座的傾角、總數、面數與相位。